Modeling and Damage/Failure Control of Spacecraft Pressurized Structures Subject to Orbital Debris Impact

轨道碎片的危害是国际上对天基基础设施安全和可靠性的日益关切--由于碰撞涉及的速度非常高，平均约为11公里/秒，即使是微小的粒子也可能损坏、降低或摧毁航天器。地球轨道上人造物体的数量稳步增加，由于2007-2009年发生的一系列事件，在过去四年里，掌握这个问题变得更加关键。今天，空间监视网络正在跟踪19000多个直径约10厘米或更大的物体。据估计，有超过30万个直径大于1厘米的无法追踪的物体，以及数百万个直径较小的物体[2]。屏蔽是航天器为进入空间碎片环境而开发的最传统的保护方法。从概念上讲，它由一个保险杠组成，它被放置在距离压力墙很小的距离处。屏蔽和增压壁穿孔都有可能导致航天器失效。拟议的研究计划将集中在屏蔽低压航天器增压舱的结构完整性上，以及部分研究用于高内压航天器系统的充气压力容器。申请者将模拟多层保护系统的穿透过程和与加筋压力墙上的冲击损伤形成相关的开裂现象。建议的模拟程序和软件将作为预测结构响应的工具，并使设计者能够开发“结构+盾构”配置，在盾构和加固的管壁被穿孔的情况下提供“简单的穿孔”条件而不会破裂。

The hazard from orbital debris is a growing international concern for the safety and reliability of space-based infrastructure - even small particles can damage, degrade, or destroy spacecraft due to the very high velocities involved in a collision, on the average about 11 km/sec . The number of man-made objects in Earth orbit has increased steadily, and it has become a lot more crucial to get a handle on the subject over the past four years because of the series of incidents happened in 2007-2009. Today the Space Surveillance Network is tracking more than 19,000 objects approximately 10 centimeters in diameter or larger. It is estimated that there are over 300,000 untrackable objects with a diameter larger than one centimeter, and millions smaller [2].Shielding is a most traditional method of protection of spacecraft developed for a mission into space debris environment. Conceptually it consists of a bumper that is placed at a small distance away from the pressure wall. The case of both shield and pressurized wall perforation presents a potential for the spacecraft failure.The proposed research program will be focused on the structural integrity of the shielded low-pressure spacecraft pressurized modules and partially on the gas-filled pressure vessels for onboard spacecraft systems with high internal pressure. The applicant will simulate the process of penetration of the multi-layered protective system and cracking phenomena associated with the formation of the impact damage on the reinforced pressure wall. The proposed simulation procedure and software will serve as a tool to forecast the response of structure and enable the designer to develop the "structure+shield" configurations which provide "simple perforation" conditions without bursting in cases where the shield and reinforced vessel wall are perforated.